Tissue tension detection system

ABSTRACT

An apparatus and a method for determining an amount of tension applied to first and second organ sections during a surgical procedure is disclosed. The apparatus includes first and second contacts on a surgical fastener applier that are operably coupled to a tension gauge and a tension indicator. The contacts may be repositionable between a retracted position and an extended position. The tension indicator may include audible and/or visual indications and/or alarms for the amount of tension applied to the first and second organ sections. Alternatively, the apparatus includes an elongate member attached to the organ sections, wherein a change in the characteristics of the member indicates an amount of tension applied to the organ sections.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to, and the benefit of, U.S.Provisional Patent Application Ser. No. 60/687,214, filed on Jun. 3,2005, the entire disclosure of which is incorporated by referenceherein.

BACKGROUND

1. Technical Field

The present disclosure relates to a method and/or apparatus formeasuring the tension in body tissue. More particularly, the presentdisclosure relates to a method and/or apparatus for measuring thetension in body tissue at a site of a surgical anastomosis.

2. Background of Related Art

Anastomosis is the surgical joining of separate hollow organ sections.Typically, an anastomosis procedure follows a surgical procedure inwhich a diseased or defective section of hollow tissue is removed andthe remaining end sections are drawn together and joined. Depending onthe desired anastomosis procedure, the end sections may be joined byeither circular, end-to-end, or side-to-side organ reconstructionmethods.

In a known circular anastomosis procedure, two ends of organ sectionsare drawn together and joined by means of a stapling device which drivesa circular array of staples through the end of each organ section andsimultaneously cores any tissue interior of the driven circular array ofstaples to free a tubular passage. Examples of devices for performingcircular anastomosis of hollow organs are described in U.S. Pat. Nos.6,053,390; 5,588,579; 5,119,983; 5,005,749; 4,646,745; 4,576,167; and4,473,077, each of which is incorporated herein in its entirety byreference. Typically, these devices include an elongated shaft having ahandle portion at a proximal end thereof to effect actuation of thedevice and a staple holding component disposed at a distal end thereof.An anvil assembly including an anvil shaft with attached anvil head ismounted to the distal end of the device such that the anvil head ismovable towards the staple holding component. The two ends of the organsections are drawn together and clamped between the anvil head and thestaple holding component of the device by securing one end of the organsection to the anvil assembly, securing the other end of the organsection about the staple holding component, and moving the anvil headtowards the staple holding component. The clamped tissue is stapled bydriving one or more staples from the staple holding component so thatthe ends of the staples pass through the organ sections and are deformedby the anvil head. An annular knife is concurrently advanced to coretissue within the hollow organ to free a tubular passage within theorgan. Typically, this procedure is conducted endoscopically orlaparoscopically using endoscopic instruments.

Although the circular anastomosis procedure described above has providedsubstantial improvements to surgical procedures requiring anastomosis,additional improvements are desired. For example, when the two ends ofthe organ sections to be anastomosed are drawn together, tension isgenerated in the organ sections. Because of the type of surgery, it canbe difficult for a surgeon to determine how much tension is being or hasbeen applied to the organ sections at the anastomotic site. Excessivetension on the organ sections at the anastomotic site may result incomplications, e.g., strictures, postoperative leaks, necrosis, etc.

Accordingly, it would be desirable to provide a surgical apparatusand/or method for measuring the tissue tension at an anastomotic siteand providing a surgeon with immediate data indicating the magnitude ofthe tension. It would also be desirable to provide an apparatus which issuitable for use with a circular anastomosis device and could measurethe initial and residual tension at an anastomotic site during asurgical procedure.

SUMMARY

In one embodiment, an apparatus positioned on a circular anastomosisfastener applier is provided in accordance with the principles of thepresent disclosure. The apparatus includes a first contact located on ananvil assembly and a second contact positioned on a staple cartridge.The first and second contacts may be movable between an extendedposition for contacting the organ sections and a retracted position. Theanvil assembly is repositionable towards and away from the staplecartridge. The first and second contacts are operably connected to atension gauge, which provides a signal to a tension indicator. Thetension indictor provides visual and/or audible indication of the amountof tension applied to first and section organ sections that are to beanastomosed. As the first organ section is moved towards the secondorgan section, the first contact is moved towards the second contact,thereby providing an input for the tension gauge and ultimately anindication on the tension indicator as to the amount of tension appliedto the organ sections. The tension indicator may be located on a housingof the fastener applier or may be remotely located therefrom. Inaddition, the tension indicator may include audible and/or visual alarmsthat alert the operator that a predetermined tension has been achieved.

In another embodiment, the first and second contacts are fixed inposition on the anvil assembly and the staple cartridge.

In a further embodiment, a device is provided for attachment to firstand second organ sections in accordance with the principles of thepresent disclosure. The attached device may be viewed with an endoscope.The device is a generally elongate member, wherein one end of the memberis attached to a first organ section and an opposing end is attached toa second organ section. As the organ sections are drawn together,tension applied to the organ sections is also applied to the member.When a predetermined amount of tension is applied, the member may changecolor or one of its physical dimensions (i.e. length, width, orthickness). Alternatively, one or both ends of the member may separatefrom its attachment point to an organ section. Further still, the membermay be positioned such that there is a predetermined amount of slack inthe member prior to the anastomotic procedure. As the organ sections aredrawn towards one another, the slack in the member is taken up. When thepredetermined amount of tension is achieved, the member will be taut,thereby providing visual indication to the operator.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the presently disclosed apparatus are described hereinwith reference to the drawings, wherein:

FIG. 1 is a front perspective view of an embodiment of the presentlydisclosed apparatus;

FIG. 2 is a front perspective view of an alternate embodiment of thepresently disclosed apparatus;

FIG. 3 is a side view of another embodiment of the presently disclosedapparatus located at an anastomotic site between two organ sections;

FIG. 4 is a side view of a further embodiment of the presently disclosedapparatus located at an anastomotic site between two organ sections withno tension applied to the organ sections; and

FIG. 4A is a side view of the apparatus of FIG. 4 with tension appliedto the organ sections.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the presently disclosed method and apparatus formeasuring tissue tension at an anastomotic site will now be described indetail with reference to the drawings wherein like numerals designateidentical or corresponding elements in each of the several views. As iscommon in the surgical apparatus art, the term proximal will refer to alocation on the device closer to the operator of the device, e.g.,surgeon, while the term distal will refer to a location on the devicefurther away from the operator of the device.

FIG. 1 illustrates one embodiment of the presently disclosed apparatusfor measuring tissue tension at an anastomotic site shown generally as10. Apparatus 10 is supported on a circular anastomosis fastener appliershown generally as 20. Apparatus 10 includes a pair of contacts or leads12 and 14 which are positioned at a distal end of circular anastomosisfastener applier 10. Contact 12 includes a first end positioned toextend through an opening 16 formed in an anvil assembly 22 of fastenerapplier 20. A second end of contact 12 communicates with a tension gauge(not shown), e.g., strain gauge, supported within housing 24 of fastenerapplier 10. Contact 14 includes a first end positioned to extend throughan opening 19 defined in a staple holding component or staple cartridge26 of fastener applier 20. A second end of contact 14 communicates withthe tension gauge in housing 24 (not shown). Contacts 12 and 14 arepositioned to contact each organ section adjacent the anastomotic siteto supply a signal indicative of the magnitude of tissue tension to thetension gauge. The tension gauge translates the signal sent by contacts12 and 14 into data identifying the magnitude of tension in the organsections. Contacts 12 and 14 can be connected to the tension gauge bywires or the like. In one embodiment, a tension indicator 30 issupported on housing 24. Tension indicator 30 communicates with thetension gauge to display in real time the tension in the organ sections.It is envisioned that fastener applier 20 may include a part which isconnectable to a strain gauge and indicator which are located externallyof housing 24.

During an anastomotic procedure, anvil assembly 22 is repositionedtowards staple cartridge 26 and moves a first organ section towards asecond organ section, thereby applying an amount of tension to the organsections. Anvil assembly 22 is repositionable, in relation to staplecartridge 26, throughout a plurality of positions including a firstposition that is spaced apart from staple cartridge 26 and a secondposition that is in close cooperative alignment with the staplecartridge 26.

In one embodiment, contacts 12 and 14 are retractable into and out ofopenings 16 and 19, wherein contacts 12, 14 are repositionable betweenan extended position and a retracted position. In one embodiment,contacts 12 and 14 are extended from openings 16 and 19 in response toapproximation of the anvil assembly 22 and staple holding component 24.Alternatively, a manual switch may be provided to extend the contacts.

FIG. 2 illustrates an alternate embodiment of the presently disclosedapparatus for measuring tissue tension at an anastomotic site showngenerally as 100. Apparatus 100 is similar to apparatus 10 in thatapparatus 100 includes a first contact 112 mounted on an anvil assembly122 of fastener applier 120 and a second contact 114 mounted on a stapleholding component or staple cartridge 124 of fastener applier 120.However, contacts 112 and 114 are flat contacts which are mounted on anouter rim of both anvil assembly 122 and staple holding component 124 ata position to contact organ sections at a location adjacent theanastomotic site. Each contact 112 and 114 communicates with a tensiongauge (not shown) supported within fastener applier 120 whichcommunicates with a tension indicator 130 as discussed above withrespect to apparatus 10. As discussed above, it is envisioned that thetension gauge and indicator may be located externally of the fastenerapplier.

In a further embodiment, tension indicators 30, 130 may include anaudible and/or visual alarm indicator (i.e. red light, buzzer, horn,bell, etc.) that informs the operator that a predetermined amount oftension is being applied to the organ sections. The setting for thealarm indicator is operator adjustable and the procedure to be performedis one of several criteria that is considered when establishing thepredetermined amount of tension for the alarm setting.

FIG. 3 illustrates another embodiment of the presently disclosedapparatus for measuring tissue tension shown generally as 200 which isseparate from a fastener applier. Apparatus 200 can be applied across ananastomotic site 230 to produce a reference indication of the magnitudeof the tension where the organ sections are joined. Apparatus 200includes an elongated member 210 formed of a material which bridgesanastomotic site 230 and is, in one embodiment, initially slack. Whenexcess tension exists in the anastomosed tissue, the material goes tautor releases from the tissue. In another embodiment, member 210 issecured to organ sections 232 and 234 using an adhesive or the like.Member 210 can be monitored endoscopically using an endoscope or otherviewing equipment. Although apparatus 200 is illustrated as a strip ofmaterial, it is also contemplated that apparatus 200 may be a suture orany other material for maintaining the two sections of the anastomoticsite in close approximation. It is further contemplated that apparatus200 may be formed of a biocompatible and/or bioabsorbable material.

In another embodiment shown in FIG. 4, device 300 is formed of a body ofmaterial 310 which can be visualized via x-ray, MRI, CT scan, ultrasoundor any other known device. Body of material 310 is positioned to bridgean anastomotic site 330. In one embodiment, when excess tension ispresent in the tissue or organ sections 332 and 334, body 310 undergoesa physical change to indicate excess tension at anastomotic site 330,e.g., body 310 may be stretched (see FIG. 4A), such that the change inthe width and/or length of body 310 is indicative of the change intension applied to organ sections 332 and 334. Further still, changes tothe thickness of body 310 indicate the change in tension applied toorgan sections 332 and 334. It is envisioned that other changes mayoccur upon application of tension to body 310, e.g., a color change mayoccur from a bioabsorbable marker, or a release from the organ sectionsmay indicate a change in tension, etc.

The embodiments illustrated in FIGS. 3-4A are configured for measuringthe tension applied to organ sections 232 and 234 or 332, 334 prior toapproximation of the organ sections with a surgical stapling apparatusas well as during approximation and subsequent to the approximation.Further still, the disclosed embodiments are capable of measuring andindicating the amount of tension applied to the organ sections before,during, and after the firing of surgical staples from the surgicalstapling apparatus. It is contemplated that devices 200, 300 may beformed from an elastic material as well as non-elastic materials.

In one embodiment, device 200 (FIG. 3) is attached to organ sections232, 234 prior to approximation of organ sections 232, 234. This occursafter a section of the subject organ is removed between organ sections232, 234. Device 200 is attached using known endoscopic techniquesthrough an access port (e.g. cannula) (not shown). Once attached, device200 may be monitored through the access port using an endoscope (notshown). As organ sections 232, 234 are approximated using a circularanastomosis fastener (i.e. apparatus 10 as shown in FIG. 1) tension isapplied to organ sections 232, 234. If the applied tension exceeds apredetermined amount, device 200 may detach at one or both attachmentpoints or have a certain amount of slack between the attachment points.Specifically, once device 200 is attached to the spaced apart organsections 232, 234, movement of the organ sections towards one another(i.e. approximation) reduces the tension applied to device 200 andcauses it to sag or go slack, whereupon, device 200 may detach from oneor both of its attachment points.

In an alternate embodiment, device 200 is attached as describedhereinabove to organ sections 232, 234 after approximation, but prior tojoining organ sections 232, 234. In this configuration, the practitionerobserves device 200 as before. If the tension applied to organ sections232, 234 exceeds a predetermined amount during the joining of thesections, device 200 may detach from one or both of the organ sectionsor go slack, as discussed hereinabove.

In a further embodiment, device 200 is attached as discussed hereinaboveto organ sections 232, 234 after organ sections 232, 234 areanastomosed. In this configuration, device 200 is observed as before,wherein tension in the anastomosed organ sections 232, 234 will createtension in the attached device 200. If the tension exceeds apredetermined amount, device 200 may stretch and/or deform, therebyindicating an excess tension condition. Alternatively, device 200 mayinclude a sac of ink or dye that is released upon exceeding apredetermined amount of tension.

In another embodiment, a marker which reacts to strain or tension isapplied to one or both of the organ sections to be joined. The markercan be an ink, polymer, or the like. When excess tension or any strainexists in the tissue sections, the marker reacts to the strain toprovide an indication or reference of magnitude. The marker's reactionto the amount of tension applied to the organ sections may includechanges in the marker's physical dimensions, a change in the marker'scolor, a reduction in an amount of slack in the marker, or separation ofone end of the marker from an organ section. In addition, markers ordevices 200, 300 may include a container (e.g. a pouch or a sac) that isembedded in marker 200, 300 such that an indicator (e.g. an ink or adye) stored in the container is released when the tension applied to theorgan sections exceeds a predetermined value.

In yet another embodiment, an electromechanical device may beoperatively connected across the anastomotic site. The electromechanicaldevice is configured to provide an output which provides an indicationor measurement of tension at the site.

It will be understood that various modifications may be made to theembodiments disclosed herein. Thus, the above description should not beconstrued as limiting, but merely as illustrative of the disclosedapparatus and method. Those skilled in the art will envision othermodifications within the scope and spirit of the claims appended hereto.

1. A method for detecting an amount tension applied to organ sections,comprising the steps of: providing a member that bridges a gap at ananastomotic site and is operably associated with a first organ sectionand a second organ section; moving the first organ section towards thesecond organ section, thereby applying tension to the organ sections;observing the member while the tension is applied to the organ sections;and determining the amount of tension applied to the organ sections byobserving changes in characteristics of the member.
 2. The method ofclaim 1, wherein the characteristics of the member are selected from thegroup consisting of: color, length, width, and depth.
 3. The method ofclaim 1, further comprising the step of: stopping movement of the organsections if the tension is greater than a predetermined value.
 4. Themethod of claim 1, wherein the step of determining the amount of tensionincludes the step of moving the first organ section towards the secondorgan section.
 5. A device for indicating the amount of tension appliedto organ sections comprising: an elongate member having opposing ends,wherein one end is attached to a first organ section and the opposingend is attached to a second organ section such that relative movement ofthe organ sections towards each other causes a change in the physicalcharacteristics of the elongate member corresponding to an mount oftension applied to the first and second organ sections.
 6. The device ofclaim 5, wherein the device has a width and the amount of tension isproportional to a change in the width of the device.
 7. The device ofclaim 5, wherein the device has a length and the amount of tension isproportional to a change in the length of the device.
 8. The device ofclaim 5, wherein the device changes from a first color to a secondcolor, the change in color corresponding to the tension applied to thedevice.
 9. The device of claim 1, wherein at least one end of the deviceseparates from at least one organ section when the amount of tensionexceeds a predetermined amount.